Issue #3375584: [random test failure] Random failure in PathWorkspacesTest

core/modules/workspaces/tests/src/Functional/PathWorkspacesTest.php

@@ -116,6 +116,11 @@ public function testPathAliases(): void {
     // Publish the workspace and check that the alias can be accessed in Live.
     $stage->publish();
     $this->assertAccessiblePaths([$path]);
+
+    // The \Drupal\path_alias\AliasWhitelist service performs cache clears after
+    // Drupal has flushed the response to the client; wait for this to finish.
+    sleep(1);
+
     $this->assertNotEmpty(\Drupal::cache('data')->get('preload-paths:/node/1'));
   }
 
@@ -159,6 +164,11 @@ public function testPathAliasesUserSwitch(): void {
 
     $this->drupalLogout();
     $this->assertAccessiblePaths([$path]);
+
+    // The \Drupal\path_alias\AliasWhitelist service performs cache clears after
+    // Drupal has flushed the response to the client; wait for this to finish.
+    sleep(1);
+
     $this->assertNotEmpty(\Drupal::cache('data')->get('preload-paths:/node/1'));
   }